Effect of Ascorbic Acid and Proline Amino Acid Supplementations on Cryosurvival and Fertility Rates of Cryopreserved Honey Bee (Apis mellifera) Semen.

This study investigated the effect of ascorbic acid (vitamin C) and proline amino acid alone or together on the quality and fertility of frozen/thawed honey bee spermatozoa. The experiments were designed to compare a single ascorbic acid, a single proline amino acid, and different combinations of ascorbic acid with proline amino acid on the cryopreservation of honey bee semen based on sperm motility, viability, intact membrane (hypo-osmotic swelling test), and fertility rates. Eight cryopreserved study groups comprised Control II with no supplement, along with groups with ascorbic acid (2 mg), proline 25 mM, proline 50 mM, proline 100 mM, and combination groups of both ascorbic acid (2 mg) and proline 25 mM, proline 50 mM, and lastly proline 100 mM groups, respectively. Using 50 mM proline in the tested groups had the greatest impact on sperm motility, viability, the percentage of spermatozoa with intact membrane, and fertility. The cryopreservation process caused a gradual decrease in motility, viability, intact membrane (p < 0.05), and fertility rates (p < 0.01) in all the tested research groups as against the fresh semen control group. Successful honey bee sperm cryopreservation and fertility are achievable when using an appropriate sperm freezing protocol and antioxidant. Proline amino acid as an antioxidant in semen extender had a more beneficial influence on sperm quality parameters and fertility. The success of cryopreservation with antioxidants is related to the chosen antioxidant in a dose-dependent manner.

Comparative assessment of various supplementary diets on commercial honey bee (Apis mellifera) health and colony performance.

A healthy honey bee stock is critical to the beekeeping industry and the sustainability of the ecosystem. The quality of the supplemental diet influences the development and strength of the colony, especially during the pollen dearth period in the surrounding environment. However, the extent to which pollen substitute protein feeding affects honey bee colony parameters is not fully known. We conducted this study to test the influence of various supplemental diets on foraging effort, pollen load, capped brood area, population density, and honey yield. The treatment groups were supplied with patties of pollen substitute diets, whereas sugar syrup was given to the control group. Our results indicated that honey bees consumed a significantly higher amount of Diet 1 (45 g soybean flour + 15 g Brewer's yeast + 75 g powdered sugar + 7.5 g skimmed milk + 7.5 g date palm pollen + 200 mL sugar syrup supplement with Vitamin C) followed by others supplemented diets. Further, pollen load, worker-sealed brood area, population strength, and honey yield differed significantly when Diet 1 was consumed instead of other supplemental diets. The proportion of biological parameters was less in the control group as compared to other treatments. This study highlights the potential of supplemental diets to improve the bee's health and colony development when the pollens availability and diversity are insufficient.

Evaluation of the standards compliance of the queen bees reared in the Mediterranean region in Turkey.

The influence of different commercial queen producers on the quality of Apis mellifera queens was assessed. It was aimed to determine the quality characteristics of queens reared by commercial queen producers located in the province of Antalya, which is an important region in queens production due to its climatic characteristics. For this purpose, the quality characteristics of a total of 105 queen bees obtained from 21 enterprises were determined. Differences between the enterprises in terms of the number of spermatozoa (P < 0.01) were determined. In terms of the diameter of spermatheca, spermatheca volume and live weight, statistical differences between the enterprises were also observed (P < 0.05). When the relationships between the measured characteristics were examined, significant values were obtained statistically between live weight and diameter of spermathecae (0.268) and spermatheca volume (0.258). It was also determined that there is a significant correlation between spermatheca diameter and spermatheca volume (0.995). The spermatheca diameter of a good quality queen bee should not be <1.2 mm, spermatheca volume 0.90 mm3 and live weight not <200 mg. Only live weight was found to be within the normal quality standard values when the average results of the quality criteria are taken into consideration. Other characters such as spermathecae diameter, spermathecae volume and number of spermatozoa in spermathecae seem to be below quality standard values.

Cryoprotective Effect of Vitamin E Supplementation of Different Extenders on Quality and Fertilizing Ability of Frozen-Thawed Brown Trout Sperm.

Vitamin E is one of the most powerful antioxidants for prevention of cell damage resulting from cryopreservation, but its efficacy for cryopreserving brown trout sperm is still unclear. In this work, the protective effect of vitamin E on quality, fertilizing capacity, and DNA damage of brown trout (Salmo trutta macrostigma) sperm after cryopreservation was evaluated. Sperm samples were diluted at the ratio of 1:10 with three different extenders (E): (E-I): 300 mM glucose, 10% egg yolk; (E-II): 33.3 mM glucose, 5.1 mM NaCl, 0.5 mM NaHCO3,, 15% DMA; and (E-III): 61.6 mM NaCl, 134.2 mM KCl, 1.9 mM CaCl2, 0.8 mM MgCl2, 2.3 mM NaHCO3 in distilled water. Each extender was supplemented with 10% DMSO and different concentrations of vitamin E at 0.1, 0.5, and 1.0 mM. Spermatozoa frozen without vitamin E (0 mM, control) and fresh sperm were also used. After dilution, the sperm was aspirated into 0.25 mL straws, frozen 3 cm above the liquid nitrogen (LN2) surface, and plunged into the LN2. Cell motility, viability, fertilization, and eyeing were determined in post-thawed samples. DNA damage was determined by the comet assay after cryopreservation. Supplementation of 1 mM vitamin E to all extenders exhibited the best cryoprotective effect in terms of sperm motility, duration of motility, viability, fertility, and DNA integrity against cryopreservation damage, compared with 0.1, 0.5, and control group (0 mM) (p < 0.05). The highest post-thaw motility (62.4% ± 0.36%), fertilization (48.2 ± 0.84), and the lowest DNA damage (7.245%) were obtained with the extender-II including 1.0 mM vitamin E (p < 0.05). Consequently, vitamin E positively affected the motility parameters, fertility, and DNA integrity, and the results suggest the addition of extenders with vitamin E as an antioxidant for the cryopreservation of brown trout sperm.

Antioxidant activities of some monofloral honey types produced across Turkey.

This study was conducted with the aim of determining the chemical, biochemical properties, and antimicrobial capabilities of some of the monofloral honeys produced in Turkey. In this study, 23 different monofloral honey samples were obtained from diverse geographical regions of Turkey. Floral origin of the honey samples was determined by melissopalinological analyses. Additionally, antioxidant properties were determined. To determine the antioxidant properties of honey samples, four test methods of total phenolic content, DPPH, iron reduction power and ß-carotene linoleic acid emulsion method were used. As a result of the antioxidant activity analysis among the honey samples, rhododendron and parsley honey showed most prominent results in terms of the amount of phenolic compounds and antioxidant activity. On the other hand, acacia and citrus honey samples showed least antioxidant activity. A positive correlation was determined between four methods. Differences between antioxidant activities of honey samples were significantly found (P < 0.01).

Effects of diluents and plasma on honey bee (Apis mellifera L.) drone frozen-thawed semen fertility.

Cryopreservation is an advanced method used to protect germplasm in liquid nitrogen. Honey bees are of special interest to protect because of their pollination activity and critical role in agriculture. There has been important progress in the cryopreservation of honey bee germplasm in recent years, leading to practical recovery of genetic material for breeding purposes following freezing. However, there remains room for improvement and the goal of the present study was to evaluate the effect of different "extenders" added post-thaw on the fertilization rate of cryopreserved honey bee semen. The purpose of adding extender post-thaw was to dilute the cryoprotectant to remove chemicals after centrifugation because of potential adverse effects. The control consisted of frozen-thawed semen without the addition of an extender; treatment groups included the addition of one of the following extenders: glucose solution, fresh ram semen plasma, fresh honey bee semen plasma, extender solution. All of the above treatments and frozen-thawed control were compared to fresh semen. For each group, 15 virgin queens were instrumentally inseminated with the semen-diluent solution and introduced into nucleus colonies to determine the brood patterns of the queens. Percentages of worker brood produced in the fresh semen, frozen-thawed semen control, glucose, fresh ram semen plasma, fresh honey bee semen plasma, and extender solution supplemented groups were 98.±1.1%, 47.0 ± 0.9%, 3.0 ± 0.8%, 0.3 ± 0.1%, 48.1 ± 4.1% and 40.3 ± 2.4%, respectively. Similiarly, spermatozoa numbers in the spermathecae of the same treatment groups were 3.6 × 106, 1.6 × 106, 7.3 × 105, 4.7 × 105, 8.1 × 105, and 4.6 × 105 spermatozoa for the same treatment, respectively. The differences in both worker brood percentage and sperm count in the spermatheca were statistically significant (P < 0.01) among all treatment groups, except the frozen-thawed control group and fresh drone semen plasma group. We found a positive correlation between sperm count in the spermatheca and the percentage of worker brood (r = 0.91). With the exception of fresh honey bee semen plasma, the fertility rate was reduced following the addition of various plasmas and diluents post-freezing.